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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Structural and kinetic insights into the mechanism for ring opening metathesis polymerization of norbornene with [RuCl2(PPh3)(2)(piperidine)] as initiator complex

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Author(s):
Fernandes, Ronaldo J. [1] ; Silva, Tiago B. [1] ; Lima-Neto, Benedito S. [1] ; Haiduke, Roberto L. A. [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL; v. 410, p. 58-65, DEC 15 2015.
Web of Science Citations: 6
Abstract

This investigation combines theoretical results and experimental data to elucidate the main kinetic and mechanism for the ring opening metathesis polymerization of norbornene by means of the {[}RuCl2(PPh3)(2)(piperidine)] complex as catalyst initiator. Structural species were defined and a kinetic profile of the entire reaction is depicted. The determined mechanism showed an associative reaction between the {[}RuCl2(PPh3)(2)(piperidine)] complex initiator and ethyl diazoacetate as the first step, resulting in a metal-carbene species. This species loses one triphenylphosphine molecule (PPh3) and the global rate-determining step is associated with a removal of the second PPh3 molecule due to an electronic trans-synergism between piperidine and this PPh3 molecule. Entropic factors are crucial to the spontaneity observed for the dissociation of both PPh3 ligands. The step following the rate-determining one is associated with the binding of a norbornene molecule and a similar trans-synergism between this monomer and piperidine activates the catalysis. This electronic effect maintains the system in a very important conformation along the catalytic chain. (C) 2015 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 10/18743-1 - Employment of multipoles from the quantum theory of atoms in molecules and kinetic studies in systems found in the interstellar medium
Grantee:Roberto Luiz Andrade Haiduke
Support type: Regular Research Grants